Bay of Biscay to W. Mediterranean. The juveniles of the species live and develop « inside the egg cases of Scyliorhinus canicula […] and several rays species, on which it feeds (Villa, 1983; Ragozzi, 1985). » (Roldán & Luque, 2010). « Once mature, the limpets leave the capsule and spawn on the nearby bottom. ». The nursery areas where theses sharks and rays like Raja clavata lay their eggs are then the places where to find A. excentrica. In Alborán sea, Roldán & Luque reported depths ranging from 50 to 200m, with the largest amount of eggs at depths of 50-100m, and the largest amount of eggs inhabited by A. excentrica at depths of 100-150m.
Original taxon: Gadinia excentrica.
Synonyms: eccentros, paradoxa…
80-100m deep, off Málaga, Andalucia, S. Spain. 11mm.
A. lateralis (Requien, 1848) sensu Aradas & Benoit, 1870.
« The pattern of colonization of the egg cases by A. excentrica is one of the most enigmatic aspects of its ecology. Villa (1983) and McLean (1985) considered that they probably penetrate in the larval stage. Dantart & Luque (1994) suggested that young specimens could also enter through the egg case ventilation slits, close to where they are generally situated within the egg case, which agrees with our observations. » (Roldán & Luque, op. cit.).
A specimen from near Atlantic, found inside shark eggs trawled at 150-200m deep, off Matalescañas, Golfo de Cádiz, Huelva, western Andalucia. 8mm.
« Cochlea ovata, oblique conoidea, glaberrima, nitens, lactea, striis exilissimis confertis longitudinaliter et transversim decussata; vertex excentrìcus, oblique recurvus, apici subjacens, postice et lateraliter situs; apertura ovata; margo simplex, acutum. — Chiocciola ovata, o meglio semi-ovata, quasi conica ed in senso obbliquo al piano della base, levigatissima, sufficientemente splendida, di color latteo e segnata da frequenti e leggere strie longitudinali e transverse incrocicchiantesi a vicenda. Vertice eccentrico, vale a dire, che è posto più in sotto del l’apice alla parte posteriore e laterale della chiocciola, e lo stesso vertice vedesi obbliquamente ricurvo. Apertura ovata. Margine semplice, acuto e tanto fragile che è soggettissimo a frangersi. Nell’interno osservasi a destra un fascio di superficiali solcature longitudinali, arcuate, raggianti ed a forma di piccolissimo ventaglio. Impressione muscolare interrotta da espansione ovata. »
A. lateralis (Requien, 1848) sensu Aradas & Benoit, in H. A. pilsbry: Manual of conchology vol. XII, Philadelphia 1890.
« Shell oval, obliquely conoidal, very smooth, shining, decussated by extremely fine radiating and concentric striae. Nucleus excentric, posterior, obliquely recurved, situated below the lateral apex. Aperture oval, margin simple, acute. » – This is a translation of Tiberi’ first lines.
100m deep, of Águilas, Murcia, S. Spain.
